I get all that simple knowledge but I feel overwhelmed like how do i approach this question.
Which compound gains the electrons i dont get it.
Do I like assign oxidation numbers to every single element in the whole equation then what do i do.

(Original post by ch0c0lat3)
I get all that simple knowledge but I feel overwhelmed like how do i approach this question.
Which compound gains the electrons i dont get it.
Do I like assign oxidation numbers to every single element in the whole equation then what do i do.

Yes you can find the oxidation number of each element in each compound
K+ and SO42- ions are spectator ions so they are not involved
Cr goes from +6 oxidation state to +3 oxidation state
C goes from +3 oxidation state to +4 oxidation state

Thank you so muchh. One question
Cr2(SO4)3, that is not involved like you said but how would i find the oxidation number if i only know that oxygen is -2. Do i use the ions or?

(Original post by BobbJo)
Yes you can find the oxidation number of each element in each compound
K+ and SO42- ions are spectator ions so they are not involved
Cr goes from +6 oxidation state to +3 oxidation state
C goes from +3 oxidation state to +4 oxidation state

(Original post by ch0c0lat3)
Thank you so muchh. One question
Cr2(SO4)3, that is not involved like you said but how would i find the oxidation number if i only know that oxygen is -2. Do i use the ions or?

You know the sulfate ion is SO42-
The sum of oxidation numbers is the charge on the species
Let oxidation number of sulfur be s
s + 4 (-2) = -2
so s = +6
then we calculate that Cr in Cr2(SO4)2 has an oxidation number +3

(Original post by BobbJo)
You know the sulfate ion is SO42-
The sum of oxidation numbers is the charge on the species
Let oxidation number of sulfur be s
s + 4 (-2) = -2
so s = +6
then we calculate that Cr in Cr2(SO4)2 has an oxidation number +3

(Original post by BobbJo)
What do you mean?
In Cr2(SO4)3, if you want to calculate the oxidation number of Cr, then let oxidation number of Cr be x
then 2x + 3(-2) = 0
x = +3
since the charge on SO42- is -2